We just bought a 2003 VW Golf for our 16 yr old daughter. It doesn’t have garage privileges. It rained here for 3 days & then we had an overnight freeze. The car sat in the driveway the whole time. We came out to use the car the morning of the freeze and found that the INSIDE of the windshield was heavily frosted. Later, we also noted that the floorboard on the driver’s side & passenger compartment behind the driver’s seat were frozen & later became full of water, of course. I noted that the gasket around the windshield wasn’t sealed to the glass & there was a trickle of water running down the inside between the dash & the driver’s door. That would explain the water in the driver’s floorboard but how does that explain the water behind the driver’s seat? There is a hump under the driver’s seat and it was dry. The seats were also dry. We are baffled. Thanks!

You may have a leak around the rear door gasket as well. Is it possible that the car was in an accident? The excess moisture in the car is causing the frost on the inside of the windshield. The windshield is cold and when the moisture inside the car condenses on the windshield, it freezes.

My suggestion is to take the car to a body shop and have them find the leaks (you have found one already), seal them up and also remove the carpeting and dry it out. Ultimately, the damp carpeting will cause the floorboards to rust out and weaken the structure of the car.

Did you get any sort of warranty with the car? If so, I suggest you visit the seller.

There may have been water in the car before you bought it, or other gaskets may be leaking. How about the rear window gasket, or the door seal? There are lots of potential places for a vehicle to leak water. The sunroof drains can also be a problem if your Golf has a sunroof.

It’s also possible that the water crested the hump by traveling through the padding under the carpet, and the carpet itself never got wet.

You WILL have to remove the carpet to dry the padding underneath, once you stop the leak. It’s the only way to completely dry the car. If you don’t remove the padding and dry it outside the car, it will hold water like a sponge and mold will grow.